Pool water pH - what is ok for my equipment?

[Drew80]

I have some mottling on my plaster after my flaky builder neglected to balance the water on first fill. I have copper deposits from my water and some calcium deposits from where the low CH sucked some of the calcium from the plaster. I think that's the explanation, at least. I confirmed that Jacks Magic #2 removes the copper and pure muriatic removes the calcium, so I'm treating with both.

I followed the directions to do the Jack's treatment, and it is very clearly lifting the stains - yay. The carton says to run the pump constantly during the treatment. I've calculated my pH to be around 5, and I've read elsewhere that a pH that low can damage your equipment. I have the heater isolated, but I'm still concerned about the pump and maybe the salt cell. Should I be ok?

 

[pooldv]

The first question is where did the copper come from? Copper can only come from adding it to the pool using chems labeled "blue" or copper based algaecide. Or it can come from copper plumbing I on the heater being dissolved into the water from low pH. Lifting the stains doesn't remove the copper it only puts it back into the water. From there it either needs to be sequestered or drained and replaced with water that doesn't contain copper.

Low pH, below 7, will dissolve copper plumbing, usually found in heaters or old pool plumbing. The filter and pump should be fine for a short period at low pH.

More here about stains, Trouble Free Pool
More here about scale, Trouble Free Pool

 

[Drew80]

I should add that I haven't actually performed a metal test, I just used the stain ID kit from Jack's Magic and the #2 solution did the trick. It's a little hard to tell what color the staining actually is because my plaster is a dark blue. Pure muriatic also seems to make a difference on the staining, so maybe it's not copper?

 

[Drew80]

I've read a few articles on pool startup that suggest I might have calcium silicate buildup. The film is pale grey and hard, not flaky like typical calcium scale. The water in the pool stayed unbalanced for about 2 months after initial fill. My builder went AWOL and I didn't know what I was doing.

I have no idea what's in Jack's #2, but it seems to be working

 

[pooldv]

Yeah, Jack's is not very open with their proprietary formulation. Calcium scale isn't really flaky either. If muriatic acid is removing it then it is most likely calcium carbonate. Calcium scale can be slowly removed by lowering your CSI to -0.8 to -0.9 and brushing with a metal brush as often as you feel like it. It will slowly dissolve the calcium back into the water. You can also sand it with wet/dry sandpaper to make it smoother if there are very rough spots.